Earthquake map of Scotland

[Brian G Turner]

An interesting piece from the BBC that shows a map of the earthquakes in Scotland over the past 50 years:

While Scotland isn't near any fault lines, what I find interesting is how many common quake zones match up to extinct volcanoes - for example, on the west coast, and also Edinburgh. I wonder if there's a connection?

That, of course, presumes the Cairngorms aren't an extinct volcanic range - else if they are, there's something fundamentally different about them compared to the others.

I'm not sure about the geology around Carlisle, though - but that's upland country and I'd make a similar guess of volcanic origins there. Just to test that theory.

 

[The Ace]

I notice a large blob in the Sidlaws (West of Dundee) and they're definitely volcanic - although long extinct.

 

[Brian G Turner]

It makes me wonder if there may be weaknesses in the Earth's crust beneath extinct volcanoes that makes it easier to experience earthquakes. I'm not sure why or what, just that I find myself jumping to that conclusion.

 

[Abernovo]

While Scotland isn't near any fault lines

Sorry? It has several of its own, including:
the Highland Boundary Fault - still seismically active, and Crieff has, I believe, the most earthquakes in Scotland (and a small seismological recording centre)*;
the Great Glen Fault - quiet, but seismically active on small scale.

The Southern Uplands also has a fault line, although I have no idea how active that is.

There are also fault lines in the seas around Scotland. All this can be found on geological maps, now searchable online.

There are lots of micro-faults all over the world.
Some seismic events are caused by movement of plates, or blocks of land (such as the Highland Boundary Fault, which is two different blocks forced together millions of years ago, but still under pressure), and others are caused by different pressures. Also seen a slope failure where two different substrates, placed together by ancient movement, lost cohesion.

*Childhood memories.

 

[hopewrites]

Speaking of childhood memories... When I was growing up all the adults were still recovering from the shock of a reawakened "dead" volcano just 13mo before my birth. Always went on and on about how you can't trust volcanoes to stay dead.


The warnings St Hellan gave them, that were ignored or misinterpreted were mostly an increase in earthquakes.


If you map gets more intense, I'd plot an evacuation rout and sort out disaster survival gear that Will function under an ash cloud.

 

[Dave]

On a geological timescale, I don't think any volcano or fault can be said to be extinct or inactive. However, there are no moving tectonic plates beneath you so I wouldn't be concerned about any end of Scottish civilisation scenarios. I was thinking that some of those dots could be from collapsing mine workings, especially coal mining around Newcastle (and those out in the sea) and Scottish lowlands, and Lead mining around Wanlockhead and in the North Pennines. There are also Roman and medieval workings for which we have no records. Interesting Map!

 

[Vertigo]

Sorry? It has several of its own, including:
the Highland Boundary Fault - still seismically active, and Crieff has, I believe, the most earthquakes in Scotland (and a small seismological recording centre)*;
the Great Glen Fault - quiet, but seismically active on small scale.

The Southern Uplands also has a fault line, although I have no idea how active that is.

There are also fault lines in the seas around Scotland. All this can be found on geological maps, now searchable online.

There are lots of micro-faults all over the world.
Some seismic events are caused by movement of plates, or blocks of land (such as the Highland Boundary Fault, which is two different blocks forced together millions of years ago, but still under pressure), and others are caused by different pressures. Also seen a slope failure where two different substrates, placed together by ancient movement, lost cohesion.

*Childhood memories.

Not sure it qualifies as a 'fault' but the Moine Thrust Belt is one of the most famous Highland features and played, I believe, a significant rile in the proof on the tectonic plate theory. The lower area of the MTB is also one of the main concentrations of earthquakes in that picture.

Also, on the active front, I was under the impression that Skye is moving away from the mainland at a relatively fast rate, geologically speaking. I seem to remember that the rate was discovered to be greater than they had thought and was causing some problems for the bridge.

 

[Brian G Turner]

Actually, I'm not sure if it proves or disproves what I speculated on, but apparently there's a long plume of lava under Scotland that originates from Iceland:

Strange mantle plume under Iceland helps keep Scotland afloat

 

[Venusian Broon]

Actually, I'm not sure if it proves or disproves what I speculated on, but apparently there's a long plume of lava under Scotland that originates from Iceland:

Strange mantle plume under Iceland helps keep Scotland afloat

From memory I did read an article on a scientist who had done some deep survey of the sea bed in the North Atlantic between Scotland and Iceland and he had picked up huge networks of 'fossilised' rivers buried beneath the mud, leading the team to speculate that the crust had at some point bulged out, probably caused by a mantle plume, enough to convert an ocean abyssal plain into dry land. Since, of course, deflated and 'Atlantis-fied'.

The interesting thing, I think, was that it was dated to have been quite recent and not connected to the famous string of extinct volcanoes across the central belt. (I think they were primarily caused by the collision of Scotland and England together when they collided hundreds of millions of years ago.)